Improvement in pistons for syringes, air-pumps



R. VANDER EMDE.

PISTONS FOR SYRINGES, AIR PUMPS, m. No.181,Z26.

Patented Aug. 15, 1876.

WITNESSES: 6%. 4 4

ATTORNEYS.

N. PETERQ PHQTO-LITHOGRAPH s Nrrnn STATES PATENT OFFICE.

REINHOLD VANDER EMDE, OF' NEW YORK, N. Y., ASSIGNOR TO HIMSELF ANDCHARLES E. KOECHLING, OF SAME PLACE.

IMPROVEMENT IN PISTONS FOR SYRINGES, AIR-PUMPS, &c.

Specification forming part of Letters Patent No. 181,226, dated August15, 1876; application filed February 28, 1876.

To all whom it may concern:

Be it known that I, REINnoLn VANDER EMDE, of the city, county, and Stateof New York, have invented a new and Improved Piston for Syringes,Air-Pumps, &c., of which the following is a specification:

In the accompanying drawing, Figure 1 represents a side elevation of asyringe with my improved piston, and Fig. 2 is a detail vertical sectionof the piston.

Similar letters of reference indicate correspondin g parts.

The invention relates to an improved pis- 'ton for syringes, air-pumps,&c., by which the working out of the pistons, which forms a frequentsource of annoyance in syringes, 860., is prevented, and the readyreplacing of the packing material rendered possible.

The invention consists of a piston-rod provided with shoulders andelastic collars, that hold intermediate leather washers placed over thesame.

In the drawing, A represents the piston-rod of a syringe. air or otherpump, in which a tightly-fitting piston is required. The pistonrod A ismade with two retaining-shoulders, a0ne at the end of the rod, the otherat a distance from the same equal to the length of the piston. Twocollars or sleeves, b, of rubber or other elastic material, are placedon the rod between the retaining-shoulders a, for holding disk-shapedleather washers d, that are placed on the rod intermediately between thecollars, and then lapped over the same in opposite direction, to formthe packing of the piston.

The elasticity of the rubber collars produces the tight fitting of thewashers to the syringe or pump barrel, and thereby the effective workingof the piston.

The Washers and collars are readily replaced when worn out by long use,but keep up their working capacity for long time by the action of therubber, without getting loose.

This piston construction overcomes, in a cheap and effective manner, theannoyance caused by the insufficient fitting of the pistons to thesyringes at present in use, and forms a better-working and moresatisfactory syringe.

lam aware that it is not new to use leather washers cushioned by rubberrings, but fastened by metal disks, the lower screwed on the piston-rod.My object is to avoid the use of metallic disks by the use of rigidshoulders on the piston, the elastic collars being readily pushed overthe shoulders.

What I claim is-- The piston A, having annular shoulders a a, incombination with the elastic collars b b and flexible washers d d, asand for the purpose specified.

REINHOLD VANDER EMDE.

Witnesses PAUL GOEPEL, T. B. MosHER.

